I have a cryoed quad from Cryoset, in my Torii MK III/IV conversion, and one of the tubes has almost completely gone out, at only 200 hours or so. It may have gone downhill sooner, but I did not notice until turning on the MK IV this morning, in near total darkness.

When you can leave you hand on a running KT66 for any length of time, you know it's a bad tube. I've got an extra quad plus a bunch of NOS RFT EL34's, so I'm not that worried, but in 25,000 Hrs+ of running a Torii I, II, III, IV, and ZSM monos, this is the first power tube failure I have experienced.

While it's very unlikely, the tube not getting warm could be a broken connection on the heater. It's most likely a tube issue, but just to be sure, you could flip-flop the two tubes on that side to verify the problem follows the tube.

Being hand made analog devices, they are bound to have some failures. But again, if they went through the Cryoset thing, you'd think they'd weed out most of the weak/faulty. I'm seeing more and more of these failures in various forums, and I'm starting to question their burn in process.

Will, good to touch base again (I did receive the tubes, thanks). I have not talked Ron yet, but will do so today. I hope it is just an oddity, if not I'll try the Genalex, I guess. I have noticed they outsell the Tung Sol by a large margin (ebay sales).

New Sensor Reflecktor Plant in Russia makes/acquired the Tong Sol brand. ...probably the Tube Mike....quality issues with New Sensor is nothing new...from way back in 2005 when they were making a knock-off of my coveted SV83 Svetlana Tubes!

Even, Mark O'Brien at Rogue Audio...I read is leary of the Tong Sol 120's reliability....will see (but he is using them).

Good news, we have alternatives as you mentioned....and could just be a fluke failure...chit happens. 12+ years with tubes....and I have had only one failure...when I had the EL34 Mono Blocks in and one EL34 failed. IT was a Winged C Sveltana...so I was surprised . -S

I just talked to Ron at Cryoset, and will send the tube back for him to check it out. I mentioned it was used in a brand new Decware amp. He said amp may not be biased properly, may have a bad resistor, or the tube may have manufacturing defects.

Hi LR, I just flip-flopped the tubes. The one in question warms up to maybe 110 degrees (just guessing). Ron said the surface of KT66's can get up to 300 degrees Farenheit. So, it's defective.

I called Ron on the phone, and to be honest I was rather upset, as I've never had a power tube go out in 10+ years. I did mention that I was referred to him by Lon and Will (First-rate guys, you know who you are!). I did not use any abusive tones or language, nor make a sarcastic remark. However, about 2/3 of the way thru our conversation, he made a comment (in a sarcastic fashion) that he did not know I was a tube expert. ...And later called me "buddy" in a similar tone.

I was a little surprised, but hey, there are all types in audio. and he may have been having a tough day. So, I'll give the benefit of a doubt.

Sorry he took that sort of tone with you Mike. I've never talked with Ron but have always had civil email conversations with him. Seems quite apparent that the tube was defective and he should well have just accepted it back with a replacement, though matched quads do complicate things. Hope you are already up and running and enjoying the IV.

Lon, Will, Lord Soth, It's really not a big deal in the scheme of things.

Will and Lon, Ron knows you, and spoke of you two as being long term customers. My experience is that some people just don't do "good phone". I often wonder how they'd interact face to face.

I've been told frequently, that I'm pretty good face to face.. Dealing with all sorts of people and spending 2 1/2 years with a Princeton trained psychologist, has helped. It's a lot easier to go thru life if you can be tolerant of others. Everyone's different.

Yes, I've talked to Kevin Deal several times in the past Kevin's OK, but he has his moments.

Brent Jesse, Brendan at Tube World, Jim McShane, and several others, are all a pleasure to talk with on the phone.

It would be nice if somebody else sold cryoed tubes. Didn't some of you guys send out tubes to be cryoed in the past? Sort of a group Decware thing? Logistics on this probably were tough, but still...

What got me off the the wrong foot with Ron, is that he thought I should have rebiased the KT66's tubes on the Torii. How many hundreds of tubes has he sold to Decware customers? And then the comment about having a bad resistor in my amp. I said "in a brand new amp?". He said "it happens". Sorry Ron, you've confused Decware amps with mainland Chinese ultra low pricepoint junk.

Oh well, I've got my 2nd quad in place, and it does sound VERY involving, just glorious! No complaints about the sound at 235 hours, although I shuddered when I saw the tilted plates in the second KT66 quad.

After this, I'll probably switch to Genalex KT66's or 77's. May not be getting them from Cryoset, though. First impressions do count.

Well I hope my Tubes do not fail. I only have 10 hours on mine. Crazy how the sound does change and seems like my soundstage is just getting higher and higher. Hey I wonder how 350B's would sound on the new Torri?

I kinda wish there were more boutique tube manufacturers these days...granted, they are always super expensive, but the Chinese...well, their manufacturing practices leave a lot to be desired in both environmental and QC areas.

Lon, Thanks for the tip on Tubeman! I have dealt with him in the past with zero problems. He has some nice stuff.

Riveraranch, I look forward to your impressions on the reissue Genelex KT66's. I have a feeling they'll work out well. The TungSols I'm using sound superb, I'm just wondering if longevity/construction will be better on the Genelex.

I may purchase a quad of the reissue Genelex KT77's soon, to see how those work out. According to Steve's well done visuals, they should be comparable to the KT66's sonically. At least in the MKIV.